The invention relates to a multi-chamber ampoule for dispensing a mixture comprising several substances.
In the fields of medicine and cosmetics, and in other fields as well, it is frequently necessary for a multi-component product to store the different components separately from one another and just mix them with one another immediately prior to application. Furthermore, it is frequently necessary or at least desirable to store the separate components as tightly sealed as possible.
It is known from EP 0 090 413 A2 to store at least two liquid, fluid, or semi-fluid substances to be mixed during application in separate cartridges which are combined to a unit of several cartridges arranged parallel to one another. The cartridges are made from a soft plastic foil and have an opening at their front end only from which the substance stored in the cartridge can exit. The front end of the cartridge usually tapers into a cone-shaped tip with its discharge opening being closed with a cap. In order to put it into use a unit comprising e.g. two cartridges is inserted into a device provided with a slidable double piston by means of which it is possible to act on the two cartridges. Before activating the double piston the two sealing caps are removed and a common mixing device is mounted onto the tubular exit sections of the two cartridges. The mixing device is provided with two inlet channels and a common exit channel which is in contact with the two inlet channels inside of the mixing device. The entire arrangement of cartridges and means for squeezing out the cartridges and mixing the substances forced out is designed comparatively complicated and cannot easily be operated.
A principally very similar dosing and mixing device is known from EP 0 313 519 A1. Here, two separate cartridges are inserted into a device, which is provided with an automated squeezing unit made from two piston rods being connected to one another. A holding mechanism for the cartridges to be inserted is provided in the housing of the device. Next to said holding mechanism, a mixing device is provided having a mixing chamber into which a mixing means extends which is exchangeable together with the cartridges. Here, the mixing chambers are also connected to the cartridges by means of two inlet channels in the form of two connecting ducts. For this purpose, each cartridge has a narrowing exit end, which is to be tightly connected to the connecting duct when inserting the cartridges into the device. On their exiting end, the cartridges are provided with a valve-like seal which breaks under pressure when the squeezing-out unit is initially put into operation. Alternatively, a tube-shaped coupling part with a sloped ring-shaped blade is provided at the cartridge side end of each connecting duct said blade severing the membrane provided at the exit end of the cartridge when the cartridges are inserted into the device. At the opposite end, the cartridges are sealed with a tear-off lid which is removed prior to the cartridges being inserted into the device. Subsequently, the end of the cartridges facing the squeezing unit is solely sealed by a piston-type element slidingly arranged in the cartridge and insertable therein. This dosing and mixing arrangement is complicatedly constructed, as well, and cannot be operated with ease.
Furthermore, a multitude of syringe fittings has been suggested allowing to dispense mixed substances from ampoules inserted into the syringe fittings. Here, on their exit or discharge side the cartridges are generally provided with a membrane being pierced by hollow needles when operated, which hollow needles mouth into a common hollow exit needle via respective connecting channels. Additionally, the connecting channels are sometimes provided with valves in order to allow a securely sealed transfer of the reacting agents into the common exiting needle. This is referred to in WO 92/10425, U.S. Pat. Nos. 5,314,412, 5,599,312.
In U.S. Pat. No. 5,542,934 the hollow piercing needles mouth into a chamber where the substances mix, and are formed by a cap bolted onto the housing of the cartridges. In AT 366 916 the two syringe bodies are inserted into a common holding arrangement. The cones of the syringe bodies extend into insertable cones of a collecting head. Inside of the collecting head, a separate feed channel leads from each cone to a cone head provided at the collecting head and having a hollow needle. AT 400 675 B describes a syringe fitting in which the syringe body is connected via a connecting piece to form a non-dismountable syringe unit in the shape of a plate into which a piston unit is inserted. Additionally, a dispensing unit that can be mounted onto the syringe unit is provided. The dispensing unit is attached to said syringe unit after removal of the cap-like seal. On its backside, the syringe unit is sealed by movable piston plugs. These plugs are provided with snapping or locking connecting means to the front ends of the piston rods. After the distribution unit is attached, the cones of the syringe bodies mouth into corresponding cone-shaped recesses, which lead into separate channels. The channels mouth into a conventional mixing canule which is attached to the dispensing piece.
It is an object of the invention to provide a multi-chamber ampoule for dispensing a mixture comprising several substances, which ampoule is designed as simple as possible and easily to be operated.
This object is achieved by the subject matter of claim 1 and 10, respectively. Preferred developments of the invention are defined in the subclaims. The multi-chamber ampoule designed according to the invention has the advantage of not requiring any separate devices for dispensing and mixing the substances. Moreover, the dispensing and mixing means are integrated in the proper multi-chamber ampoule and serve additional functions therein. The pistons remaining in the chambers, for example, serve to seal the rear openings of the chambers storing the substances and, in a preferred embodiment, these pistons form the front ends of a one-piece piston unit which does not require any separate piston plugs to be provided additionally which, again, would require a separate piston rod unit in order to shift the plugs. Simultaneously, the mixing device forms the housing for receiving the container provided with the chambers and said housing seals, cooperating with the container, the mixing chamber with respect to undesired leaks. Thus, sealing caps that would have to be removed and dispensing units to be subsequently attached are not required. On the one hand, the requirement for the operator to align, attach, and fit a dispensing unit is avoided. On the other hand, the danger of leaks is omitted which can result from connecting units not being attached correctly.
In the ampoule according to the invention, a sealed arrangement of the container with the chambers in the inner chamber or space of the housing can be guaranteed without any additional sealing elements solely by a tight contact of the walls of the container and the housing over an extended wall section. Thus, the discharge of the substances to be mixed can occur directly from the chambers of the container into the mixing chamber. Additional conduits or channels and/or cone sections to be sealingly inserted are avoided. These aspects are also true for the embodiment according to claim 10, with the function of the container according to claim 1 here being performed by the piston unit according to claim 10 and the function of the piston unit according to claim 1 being performed by the container of claim 10.
Prior to operation, according to the invention, the only manipulation requirement for the operator for putting the ampoule into operation is to open a sealing means at the front dispensing opening of the chambers. In one embodiment, a sealing foil laterally protruding from the housing is simply pulled off. This can occur by hand. In another embodiment the sealing foil is automatically pierced by housing protrusions when the container is pushed forward in the direction of the mixing chamber during the forward motion of the piston. In contrast to the hollow piercing needles known from prior art or to tubular coupling pieces having blades these housing protrusions do not form any through channels circumferentially sealed with respect to the foil but rather serve merely for perforating the foil.
In another embodiment the sealing means is a type of plug formed such that, for activating the ampoule during the forward motion of the chamber container in a direction towards the mixing chamber, said plug abuts the housing and, thereby, is pressed into the interior of the chamber whereby the plug clears the chamber dispensing opening. Here, the chamber container can be directly pressed against the housing by hand or indirectly by applying pressure onto the piston unit. Rather than separate plugs for each chamber, preferably, a common plug unit, for example a double plug is provided for a container having two chambers for substances.